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Last time, I talked about how the fast-food companies use their knowledge of neuroscience to influence you to eat unhealthy food, even when you're not hungry.

They used both the fact that sugar can be addictive as well as the fact that repeated exposure can overcome your natural impulse control.

I also talked about how they never keep you waiting. After all, to set up an addiction you want the time between the stimulus and the reward (or the time between walking into the shop and scoffing the food) as short as possible.

But the fast-food companies use a few more tricks nicked from the land of neuroscience.

Their fourth trick is that they sell stuff that is just overflowing with kilojoules. You see, thanks to a few million years of evolution, our natural impulse is to eat as much as possible whenever food is available.

Back in the old days, our restaurant was the open savannah — but it wasn't always open. Back then, the energy-dense fats and sugars were prized as a buffer (or protection) from starvation. They were also rare.

But in today's wealthy countries, food is always only a few minutes away — at the most!

Thanks to our natural impulses, which used to be protective, we will eat until we are full — and then keep on eating even more.

Unfortunately, we just mentally recalibrate upwards the level at which we think we are full.

Sure, to make themselves seem healthier, some fast-food chains carry low-energy items, like salads. But these make up a microscopic percentage of their sales.

Another trick that they use is to carry one or two items that are not too expensive, and even the occasional 'loss-leader' item. A loss-leader is something that is deliberately sold at a loss.

Why would they do this? To lead you into the store and then sell you something more expensive.

Your brain does not like the act of losing money. In fact, imaging studies of the brain show the same pattern of activity either when you stub your toe or when you lose money.

Losing hurts! In fact, the pain of losing a small sum of money is greater than the pleasure of winning exactly the same amount of money. Bargains are very attractive.

So, at your local fast-food outlet you might subconsciously realise that the food is not a healthy choice. But you don't feel too bad because you think that at least the meal is cheap.

But when you order the drink in the huge cup, you don't realise that you're paying a few dollars for something that costs them only a few cents. And everything else is expensive.

So the next time you feel tempted to buy some fast food because one single advertised item or package seems cheap, remember this: In the vast majority of cases, it is more expensive to feed yourself with fast food than it is to buy the ingredients and cook them yourself.

The sixth trick from the land of neuroscience goes all the way back to the Nobel Prize-winning Russian scientist, Ivan Pavlov, and his slobbering dogs.

Just before he fed his dogs, he rang a little bell. After some time of doing this, he rang the little bell, but didn't offer them food.

But, once conditioned to the prospect of dinner time, his dogs still slobbered and salivated mightily. They had been conditioned to link salivation, food and the little bell.

In the same way, the fast-food chains successfully condition you. They go out of their way to give you the exact same experience every time.

The inside of the shop is the same, the menu is the same, and employees in the same uniform recite the same scripted greeting to you.

The last time this experience happened, you bought some fast food. So this time, you'll probably buy some fast food again.

The seventh trick comes from research in neuroscience that tells us that the pleasure in eating food does not come purely from the taste, smell and physical act of eating.

No! A lot of the pleasure comes from past memories. One study gave children identical chicken nuggets, but in different containers. The kids thought that the food in the familiar Mac-packaging tasted better than the identical nuggets in plain packaging.

So fond memory can make grim reality seem better.

So what can a poor kid do against all of this sneaky manipulation of modern neuroscience knowledge? We'll talk about that, next time.

Comments (7)

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Aptitude Design :

06 Sep 2011 6:32:18pm

Around about 1960, when the TV kept telling me that "The Whole World Drinks Coca-Cola", I thought; if so, why do they need to have all the advertising? The same applies to the rest of it. Keep Forever Chicken & Fat Donald can go jump.

Steven :

07 Sep 2011 6:38:12am

People choose to eat fast food. Even taking into account all that fast food companies do to influence you to eat their food it still is a choice. Until those golden arches turn into a double barreled shotgun, its on the consumer to decide what is best for themselves.